This invention relates to a flame retarded polyurethane foam, and more particularly, a polyurethane foam prepared by adding to the reaction mixture a derivative compound of melamine containing the 2,2,2-trichloroethyl group.
Prior to the instant invention, polyurethane foam was made flame retarded normally by incorporating phosphorus and/or halogen containing compounds into the polyurethane formulation. One such flame retardant for polyurethane foam is 2,3-dibromo-2-butene-1, 4-diol which is described in U.S. Pat. Nos. 3,919,166 and 4,022,718. The disadvantages of this material are its relatively high cost and its poor processibility at high loadings. U.S. application Ser. No. 890,358 discloses N,N'-di(1-hydroxy-2,2,2-trichloroethyl) urea as a flame retardant additive for polyurethane foam. Although this compound is an effective flame retardant, it is soluble in the polyols used for preparing the polyurethane foam and thus decrease the load bearing properties of the foam.
The compounds of the present invention overcome the disadvantages of the prior art because they are insoluble in the polyol and thus increase the load bearing properties of flexible polyurethane foams as measured by the Indentation Load Deflection test described in ASTM D 2406-73. (The Indentation Load Deflection test is a measure of the force necessary to indent a foam sample to a specified thickness). The compounds of this invention also do not adversely affect the support (sag) factor of the foam as do prior art compounds. The support (sag) factor is measured as the ratio of the 65% Indentation Load Deflection value to the 25% Indentation Load Deflection value and is related to foam comfort.